U.S. patent application number 15/114110 was filed with the patent office on 2017-01-05 for biological yeast, method for obtaining same and uses thereof.
This patent application is currently assigned to LESAFFRE ET COMPAGNIE. The applicant listed for this patent is LESAFFRE ET COMPAGNIE. Invention is credited to Amelie BUGEON, Eric PETIT.
Application Number | 20170002309 15/114110 |
Document ID | / |
Family ID | 50729725 |
Filed Date | 2017-01-05 |
United States Patent
Application |
20170002309 |
Kind Code |
A1 |
BUGEON; Amelie ; et
al. |
January 5, 2017 |
BIOLOGICAL YEAST, METHOD FOR OBTAINING SAME AND USES THEREOF
Abstract
The present invention relates to a method for producing yeast.
It relates in particular to a method for producing biological
yeast, comprising the use of substrates of biological origin, in
particular a biological substrate which makes it possible to
supplement the nutritional requirements in the yeast in terms of
phosphorus. The method of the present invention makes it possible
to obtain biological yeast and biological yeast extracts in
accordance with European Union Regulation (EC) 834/2007. According
to the invention, the phosphorus-rich biological composition is
obtained by hydrolysis and solubilization of at least one plant
substrate of biological origin comprising from 2 to 18 g of
phosphorus per kg of product, 60% to 80% of which is in the form of
phytic acid. The preferred substrate according to the invention is
wheat bran.
Inventors: |
BUGEON; Amelie; (Courpiere,
FR) ; PETIT; Eric; (Marquette Lez Lille, FR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
LESAFFRE ET COMPAGNIE |
Paris |
|
FR |
|
|
Assignee: |
LESAFFRE ET COMPAGNIE
Paris
FR
|
Family ID: |
50729725 |
Appl. No.: |
15/114110 |
Filed: |
April 10, 2014 |
PCT Filed: |
April 10, 2014 |
PCT NO: |
PCT/FR2014/050869 |
371 Date: |
July 26, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A23L 7/104 20160801;
A23V 2002/00 20130101; C12N 1/18 20130101; A23L 33/14 20160801;
C12N 1/16 20130101 |
International
Class: |
C12N 1/16 20060101
C12N001/16; A23L 33/14 20060101 A23L033/14; A23L 7/104 20060101
A23L007/104 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 6, 2014 |
FR |
1450911 |
Claims
1. A method for culturing biological yeast on a culture medium
comprising carbon, nitrogen and phosphorus sources of biological
origins, wherein the phosphorus source is a phosphorus-rich
purified solution obtained by hydrolysis and solubilization of at
least one phytic acid-rich biological substrate comprising from 2
to 18 g of phosphorus per kg of substrate, 60% to 80% of which is
in the form of phytic acid.
2. The method as claimed in claim 1, wherein said phytic acid-rich
substrate also has a phytase activity.
3. The method as claimed in claim 1, wherein said phytic acid-rich
substrate is chosen from the group comprising: corn gluten, fatty
rice bran, rapeseed, soy cake, sunflower cake, half-white common
wheat middlings, wheat bran, rye, and common wheat flour.
4. The method as claimed in claim 1, wherein the solubilization and
hydrolysis are carried out according to the following mode: a.
milling said phytic acid-rich biological substrate, b. suspending
the product obtained in a, c. heating the suspension, d. enzymatic
deactivation of the suspension.
5. The method as claimed in claim 4, wherein the milled substrate
is suspended in water in a proportion of from 100 to 250 g of
milled product per kg of suspension.
6. The method as claimed in claim 4, wherein the suspension is
heated at a temperature of between 40 and 50.degree. C. for 5 to 20
hours.
7. The method as claimed in claim 4, wherein the suspension
comprises a phytase.
8. The method as claimed in claim 1, wherein the phytic acid-rich
substrate is wheat bran.
9. The method as claimed in claim 1, wherein the solubilization and
hydrolysis method can be added to with a treatment of protein
hydrolysis and of starch saccharification.
10. The method as claimed in claim 1, wherein the source of
nitrogen is of hydrolyzed gluten.
11. The method as claimed in claim 10, wherein the gluten
hydrolysis is carried out with an enzymatic cocktail comprising the
following enzymes: neutrase, alcalase, cristalase and
flavourzyme.
12. The method as claimed in claim 1, wherein the source of sugar
is cane and/or beet molasses.
13. The method as claimed in claim 12, wherein the source of sugar
consists of a mixture of cane molasses and beet molasses in a ratio
of between 50/50 and 80/20.
14. The method as claimed in claim 1, wherein it also comprises the
addition of sodium carbonate, lactic or citric acids and vegetable
oils.
15. A phosphorus-rich purified composition of biological origin
obtained by solubilization and hydrolysis of at least one phytic
acid-rich biological substrate, wherein said phytic acid-rich
substrate comprises from 2 to 18 g of phosphorus per kg of
substrate, 60% to 80% of which is in the form of phytic acid.
16. The composition as claimed in claim 15, wherein said phytic
acid-rich substrate has a phytase activity.
17. The composition as claimed in claim 15, wherein said phytic
acid-rich substrate is chosen from the group containing: corn
gluten, fatty rice bran, rapeseed, soy cake, sunflower cake,
half-white common wheat middlings, wheat bran, rye, and common
wheat flour.
18. The composition as claimed in claim 15, herein the
solubilization and the hydrolysis are carried out according to the
following mode: a. milling said phytic acid-rich biological
substrate, b. suspending the product obtained in a, c. heating the
suspension, d. enzymatic deactivation of the suspension.
19. The composition as claimed in claim 18, wherein the milled
substrate is suspended in water in a proportion of from 100 to 250
g of milled product per kg of suspension.
20. The composition as claimed in claim 18, wherein suspension is
heated at a temperature of between 40 and 50.degree. C. for 5 to 20
hours.
21. The composition as claimed in claim 18, wherein the suspension
comprises a phytase.
22. The composition as claimed in claim 15, wherein the phytic
acid-rich substrate is wheat bran.
23. The composition as claimed in claim 15, wherein the
solubilization and hydrolysis method can be added to with a
treatment of protein hydrolysis and of starch saccharification.
24. A method for producing biological yeast comprising the use of a
composition as claimed in claim 15 for producing biological
yeast.
25. A biological yeast obtained by means of: (1) a method for
culturing biological yeast on a culture medium comprising carbon,
nitrogen and phosphorus sources of biological origins, wherein the
phosphorus source is a phosphorus-rich purified solution obtained
by hydrolysis and solubilization of at least one phytic acid-rich
biological substrate comprising from 2 to 18 g of phosphorus per kg
of substrate, 60% to 80% of which is in the form of phytic acid, or
(2) a method for producing biological yeast comprising the use of a
phosphorus-rich purified composition of biological origin obtained
by solubilization and hydrolysis of at least one phytic acid-rich
biological substrate, wherein said phytic acid-rich substrate
comprises from 2 to 18 g of phosphorus per kg of substrate, 60% to
80% of which is in the form of phytic acid for producing biological
yeast.
26. A biological yeast extract obtained from the yeast as claimed
in claim 25.
Description
TECHNICAL FIELD OF THE INVENTION
[0001] The present invention relates to a method for producing
yeast. It relates in particular to a method for producing
biological yeast, comprising use of substrates of biological
origin, in particular a biological substrate which makes it
possible to supplement the nutritional requirements in the yeast in
terms of phosphorus. The method of the present invention makes it
possible to obtain biological yeast and biological yeast extracts
in accordance with European Union Regulation (EC) 834/2007.
TECHNOLOGICAL BACKGROUND/PROBLEM TO BE SOLVED
[0002] In order to multiply, yeast needs carbon and energy sources,
such as a mixture of glucose, fructose and sucrose sugars. It also
needs nitrogen, phosphorus, oxygen and other trace elements,
including inter alio magnesium, sodium, potassium, zinc, copper or
else manganese and growth factors including biotin, inositol,
pantothenic acid, thiamine, pyridoxine, nicotinic acid or even
para-aminobenzoic acid. In the context of the conventional
production of yeasts, sugarcane molasses or sugar beet molasses are
generally used as a combined carbon and energy source. These
molasses provide the yeast with most of its carbon, mineral, trace
element and vitamin requirements.
[0003] The nitrogen contents of yeast varies from 6% to 9% of the
dry matter of the yeast, i.e. from 37% to 56% of proteins. However,
the nitrogen provision by the molasses is largely insufficient.
Consequently, the provision of nitrogen to the culture medium is
usually carried out in the form of hydroxide or other ammonium
salts or else urea.
[0004] Molasses lacks phosphorus. The phosphorus composition of the
yeast, expressed as P.sub.2O.sub.5, is generally a third of that of
nitrogen, i.e. from 2% to 3% of the dry matter. The phosphorus is
generally added in the form of phosphoric acid or salts
thereof.
[0005] European regulations impose strict orders for the production
of biological yeast, whether it is intended for human food or
animal feed and whatever the application for which said yeast is
intended (bread making, yeast extracts, wine making, etc.).
[0006] Thus, only substrates produced according to the biological
mode can be used (Regulation (EC) No. 834/2007). However and by
special dispensation (Regulation (EC) No. 889/2008 after
modification by Regulation (EC) No. 1254/2008), 5% of nonbiological
yeast extract or autolysate (YEX) calculated on the basis of the
dry matter of the biological substrates are authorized provided
that operators are not in a position to obtain yeast extract or
autolysate from biological production.
[0007] This dispensation to use nonbiological YEX was introduced by
the legislator in order to supplement the provisions of nitrogen,
phosphorus, vitamins and minerals absolutely required for the
production of biological yeast.
[0008] Indeed, the industrial manufacture of yeast can be envisaged
only if the nutritional requirements of the yeast are perfectly
covered.
[0009] When the biological substrates used for the manufacture of
biological yeast are cane and beet molasses and also a protein
source isolated from an agricultural product resulting from
biological agriculture, these substrates provide, in sufficient
amount, the sugar, the nitrogen and a part of the minerals and
vitamins required for growth.
[0010] On the other hand, the phosphorus requirement is not met. In
this case, the use of the yeast autolysate makes it possible to
cover it. However, even by selecting a particularly phosphorus-rich
autolysate, the weight limitation of its use only incompletely
covers the requirements of an industrial manufacture and, as a
result, limits the quality and the regularity thereof.
[0011] The provision of a phosphorus-rich substrate produced
according to the biological mode would make it possible to solve
the above-mentioned problem and to thus produce biological yeast
and biological yeast extracts in accordance with European Union
Regulations.
[0012] The applicant has found that certain phytic acid-rich
products of biological origin are, after solubilization and
hydrolysis, a source of phosphorus that can be efficiently
assimilated by yeast.
SUMMARY OF THE INVENTION
[0013] A first subject of the invention is a method for producing
biological yeast, comprising the use of carbon, nitrogen and
phosphorus sources of biological origins.
[0014] The phosphorus source of biological origin according to the
invention is a phosphorus-rich purified solution obtained by means
of a method comprising at least one step of solubilization and
hydrolysis of a phytic acid-rich substrate or a mixture of phytic
acid-rich substrates of biological origin.
[0015] Another subject of the invention is a purified solution of
biological origin which is rich in phosphorus that can be
assimilated by yeast.
[0016] Another subject of the invention is the use of the
phosphorus-rich purified solution of biological origin for
producing biological yeast.
[0017] Another subject of the invention is a biological yeast in
accordance with European Union Regulations.
[0018] A subject of the invention is also a biological yeast
extract in accordance with European Union Regulations.
DETAILED DESCRIPTION OF THE INVENTION
[0019] The first subject of the present invention is a method for
producing biological yeast, comprising the use of substrates of
biological origins capable of providing all the nutrients required
for the growth of the yeast.
[0020] These substrates are preferentially molasses as a source of
sugars, a source of hydrolyzed biological proteins as a source of
nitrogen and at least one phosphorus-rich purified solution as a
source of phosphorus.
[0021] The method of the invention also comprises the use of other
substances required for the growth of the yeast, chosen from those
authorized by the European Regulation, such as sodium carbonate,
lactic or citric acids and vegetable oils.
[0022] The method of the invention uses molasses of biological
origin as a source of sugar. According to one form of the
invention, the molasses used is chosen from cane molasses and beet
molasses. In order to take advantage of their different
compositions in terms of minerals and vitamins, it is preferable
according to the invention to jointly use cane and beet molasses in
a ratio of between 50/50 and 80/20. According to one preferred form
of the invention, the cane molasses/beet molasses ratio is between
65/35 and 75/25, and more preferentially close to 70/30.
[0023] According to the invention, the biological source of
nitrogen is a source of hydrolyzed biological proteins, chosen from
rice, pea, potato, wheat, soy, alfalfa, spirulina and gluten
proteins.
[0024] According to one preferential form of the invention, the
biological source of nitrogen is hydrolyzed gluten.
[0025] The hydrolysis of the biological source of nitrogen can be
carried out using an enzymatic cocktail which makes it possible to
have a degree of solubilization of the dry matter close to 80% and
a nitrogen yield of 80% to 85%. This enzymatic cocktail comprises a
mixture of endoproteases and exopeptidases, preferentially all or
part of the mixture Neutrase, Alcalase, Cristalase and Flavourzyme.
These enzymes, which are non-GMO, are authorized for the
manufacture of protein hydrolysates.
[0026] According to the invention, the provision of phosphorus is
covered by the use of a solution, of biological origin, which is
purified and rich in phosphorus. This solution is obtained by
solubilization and hydrolysis of a phytic acid-rich plant substrate
of biological origin, the phosphorus being released in the form of
inorganic phosphate after solubilization and hydrolysis of the
phytic acid.
[0027] According to the invention, the "phytic acid-rich biological
substrate" is intended to mean a plant substrate of biological
origin comprising from 2 to 18 g of phosphorus per kg of substrate,
60% to 80% of which is in the form of phytic acid.
[0028] The phytic acid-rich substrate according to the invention is
chosen from the group of plants listed in table I below:
TABLE-US-00001 TABLE I Total phosphorus contents, phytic phosphorus
to total phosphorus ratio and phytase activity of various raw
materials (according to Sauvant 2002). P (g/kg raw) mean Phytic
Phytase Group (standard P/total activity of Name deviation) P (%)
(U/kg) interest Corn gluten 8.9 (1.5) 65 0 1 Fatty rice bran 16.1
(2.1) 85 120 1 Rapeseed 6.6 (0.9) 70 0 1 Rapeseed cake 11.4 (0.9)
60 10 1 Soy cake 6.2 (0.5) 60 20 1 Sunflower cake 10.1 (1.4) 85 0 1
Half-white common wheat 8.7 (1.4) 80 2590 2 middlings Wheat bran
9.9 (1.1) 80 1770 2 Rye 3 (0.3) 65 5350 3 Low-grade common 3.6 80
3080 3 wheat flour
[0029] As indicated in the table above, certain phytic acid-rich
substrates exhibit a more or less marked phytase activity. The
phytic acid-rich substrate of biological origin according to the
invention will be chosen according to either: [0030] its high
phosphorus content (group of interest 1); [0031] its high
phosphorus content and its richness in phytase activity (group of
interest 2); or [0032] its richness in phytase activity (group of
interest 3).
[0033] In addition to the phosphorus, essentially present in the
form of phytic acid, these compounds also contain proteins or even
starch, compounds that are very useful for yeast growth.
[0034] For example, the average composition of wheat bran and of
soy cake is:
[0035] for wheat bran: [0036] dry matter content: 87% on product as
is (TQ) [0037] phosphorus: approximately 1% (TQ), i.e.
approximately 10 g of phosphorus per kg of product, in the form of
phytic acid at 80%. Phytase activity 1770 U/kg [0038] proteins: 15%
to 18% (TQ) [0039] starch: 20% (TQ)
[0040] for soy cake: [0041] dry matter content: 88% to 93% (TQ)
[0042] phosphorus: 0.6% (TQ), (i.e. approximately 6 g of phosphorus
per kg) in the form of phytic acid (60%) and of phospholipids.
Phytase activity 20 U/kg [0043] proteins: 41% (TQ).
[0044] It is necessary to hydrolyze these compounds in order to
release the substances that can be assimilated by the yeast, since
neither the phytic acid nor the proteins and the starch can be
assimilated as they are by the yeast.
[0045] Phytic acid, of chemical formula
C.sub.6H.sub.18O.sub.24P.sub.6, consists of an inositol ring and 6
phosphate groups (InsP6). Under the action of a phytase, the phytic
acid is hydrolyzed in the form of inorganic monophosphate and of
myoinositol phosphates having a lower degree of phosphorylation
(InsP5 to InsP1) and free myoinositol in certain cases as described
in EP 1 910 531 B1.
[0046] The phytase used for this hydrolysis may be endogenous to
one of the rich substrates used in the mixture to be hydrolyzed, or
exogenous in the case where the mixture of plants to be hydrolyzed
is deficient in endogenous phytase activity.
[0047] It should be noted that wheat bran does not require the use
of exogenous phytase. The solubilization of the phosphorus of wheat
bran without recourse to exogenous phytase activity is particularly
advantageous since the provision of phytase not derived from GMOs
(biological regulation obligation) is difficult.
[0048] The mixture of plants, such as those described in table I,
can allow the provision of phytase activity even though the plant
used might not at first glance be described as phosphorus-rich
(substrates of group of interest 3 of table I).
[0049] The solubilization and hydrolysis of phytic acid are carried
out according to the mode comprising at least the following steps:
[0050] milling the phytic acid-rich biological substrate, [0051]
suspending in water and heating the suspension, and [0052]
enzymatic deactivation.
[0053] By way of indication, the milling is carried out using a
hammer mill equipped with an 800 .mu.m grill. However, any type of
mill can be used.
[0054] The suspending in water is carried out in a proportion of
from 100 to 250 g and preferably from 160 to 180 g of milled
product per kg of final suspension. The suspension is heated at a
temperature of between 40 and 50.degree. C. for 5 to 20 hours.
[0055] For the enzymatic deactivation, the suspension is brought to
a temperature of 90.degree. C. for a period ranging from 15 to 30
minutes, also enabling pasteurization of the substrate.
[0056] It is sometimes necessary to add an exogenous phytase to the
suspension so as to reinforce or supplement the endogenous phytase
activity. In this case, the exogenous phytase is used in a
proportion of 15 to 25 g per kg of milled product.
[0057] At the end of these treatments, the suspensions are decanted
and/or clarified and/or filtered.
[0058] In order to maximize the recovery of the solubilized matter,
the decanting sludges, the centrifugal clarification sludges or the
filtration cakes can be washed, and the washing waters are then
combined with the initial supernatant. All of the solutes can then
be concentrated.
[0059] The analysis of the harvested concentrated supernatants and
washing waters shows that 80% to 90% of the phosphorus contained in
the initial substrate is solubilized.
[0060] According to one preferred mode of the invention, the phytic
acid-rich substrate is wheat bran.
[0061] In certain cases, the solubilization of the phosphorus can
be added to using more conventional treatments of protein
hydrolysis (mixture of endo and exopeptidases) and of starch
saccharification (use of a mixture of amylase and
amyloglucosidase).
[0062] Another subject of the invention is the use of a
phosphorus-rich purified solution, as described above, in a method
for producing yeast, in particular in a method for producing
biological yeasts, comprising the use of substrates of biological
origin.
[0063] The method for producing the yeast of the invention is
carried out under the culture conditions normally used for
producing conventional yeast, likewise with regard to the operating
conditions for recovering, drying and packaging the yeasts
produced.
[0064] The present invention makes it possible in particular to
uncouple the provisions from the main ingredients required for the
yeast growth, namely the sugar, nitrogen source, phosphorus source
and air. This uncoupling is desired in order to control the final
composition of the yeast manufactured.
[0065] Another subject of the invention is the biological yeast as
produced by means of the method of the invention.
[0066] Another subject of the invention is the use of the
biological yeast of the invention in the bread making field and the
alcohol production field, and more generally for human food and
animal feed.
[0067] The yeasts of the invention are particularly useful for
producing biological yeast extracts.
[0068] Another subject of the invention is a biological yeast
extract obtained from the biological yeasts of the invention.
[0069] The following examples illustrate the invention without
limiting the scope thereof.
EXAMPLES
Example 1
Solubilization and Hydrolysis of Gluten
[0070] It is known that hydrolysis of plant proteins by a purified
protease (of papain or alcalase type) can be improved by adding
yeast undergoing autolysis (EP0578572A, US201202888587).
[0071] In order to demonstrate the effectiveness of the enzymatic
cocktail proposed by the invention, the applicant carried out the
following three tests: [0072] Recipe 1: gluten of Blattman origin,
biological brewer's yeast in which autolysis has been brought
about, papain [0073] Recipe 2: gluten of Celnat origin, biological
baker's yeast in which autolysis has been brought about, papain
(cristalase), neutrase and alcalase [0074] Recipe 3: gluten of
Celnat and/or Blattman origin, Neutrase, Alcalase, Flavourzyme.
[0075] Firstly (recipe 1), only biological brewer's yeast in which
autolysis has been brought about was used in combination with
papain (cristalase). Next, secondly, and in order to compensate for
the loss of proteolytic activities of the brewer's yeast cells, two
supplementary enzymes were used (neutrase and alcalase) in
combination with biological baker's yeast in which autolysis has
been brought about (recipe 2).
[0076] Finally, the papain is replaced with Flavourzyme (mixture of
endoprotease and exopeptidase) and the use of biological baker's
cream yeast in which autolysis has previously been brought about
was abandoned.
[0077] The matter balances of these 3 hydrolysis recipes are
correlated in table II.
TABLE-US-00002 TABLE II Overall results of the various gluten
hydrolysis recipes used during the biological yeast tests Recipe
Recipe 1 Recipe 2 Recipe 3 Raw materials (in kg DM/T nonclarified
final hydrolysate) Gluten nature Blattman Celnat Celnat Celnat
Blattman DM content 93.9% 93.4% 93.6% 94.1% 92.6% concentration 23
kg DM/T 103 kg DM/T 167 kg DM/T 138 kg DM/T 152 kg DM/T DM ratio
50% 90% 100% 100% 100% Yeast nature Brewer's Baker's concentration
23 kg DM/T 10 kg DM/T DM ratio 50% 10% Enzymes (in kg DM/T DM to be
hydrolyzed) Protein hydrolysis Papain 3.34 kg DM/T 21.43 kg DM/T
Neutrase 19.10 kg DM/T 3.20 kg DM/T 4.78 kg DM/T 4.85 kg DM/T
Alcalase 17.85 kg DM/T 2.58 kg DM/T 3.86 kg DM/T 3.92 kg DM/T
Flavourzyme 0.11 kg DM/T 0.16 kg DM/T 0.16 kg DM/T Solubilization
Dry matter content (kg DM/T 43.0 kg DM/T 99.0 kg DM/T 153.3 kg DM/T
128.2 kg DM/T 135.5 kg DM/T supernatant) yield (% of DM 81% 73% 80%
83% 79% involved) Nitrogen yield (% of N 86% 82% 80% 84% 85%
involved) Amount of sludge after lab centrifugation 4000 G-10 min
(in kg DM/T nonclarified hydrolysate) amount 7 kg DM/T 31 kg DM/T
38 kg DM/T 25 kg DM/T 29 kg DM/T sludge DMS 10% 28% 30% 27% 28%
content
[0078] In terms of solubilization of the dry matter implemented,
only recipe 2 exhibited a lower effectiveness (73% compared with
80-83%).
[0079] In terms of solubilization of the nitrogen, no clear
difference is apparent between the three recipes tested. Use of
Flavourzyme therefore appears, overall, to effectively replace the
use of cream yeast (recycled biological or brewer's yeast, in which
autolysis has been brought about beforehand).
[0080] Recipe 3 enables a nitrogen yield close to 85%, which is
largely sufficient, and a degree of protein degradation of 39%
which is quite satisfactory, the degree of degradation being the
ratio between the amino nitrogen content of the hydrolysate
(resulting from the hydrolysis) and the total nitrogen content of
the hydrolysate.
Example 2
Solubilization and Hydrolysis of wheat bran and of Soy Cake
[0081] The operating conditions of the various treatments applied
and also the results obtained are described hereinafter:
[0082] Wheat bran: [0083] milling of the bran. By way of
illustration, a hammer mill equipped with an 800 .mu.m grill was
used during the pilot tests; [0084] suspending in water in a
proportion of 165 g of milled bran per kg of suspension; [0085]
heating at 40 to 50.degree. C. for 5 to 20 hours; [0086] addition
of exogenous phytase, the reaction takes place by virtue of the
endogenous phytase activity of the bran; [0087] enzymatic
deactivation at 90.degree. C. for 30 minutes.
[0088] Soy cake: [0089] milling of the cake. By way of
illustration, a hammer mill equipped with an 800 .mu.m grill was
used during the pilot tests; [0090] suspending in water in a
proportion of 165 g of milled cake per kg of suspension; [0091]
heating at 40 to 50.degree. C.; [0092] addition of exogenous
phytase (Sumizyme PHY) at the dose of 20 g per kg of crude cake
used, the endogenous phytase activity being virtually zero; [0093]
treatment duration 5 to 20 hours, temperature regulated; [0094]
enzymatic deactivation at 90.degree. C. for 30 minutes.
[0095] At the end of these treatments, the bran or cake suspensions
are decanted and/or clarified and/or filtered.
[0096] In order to maximize the recovery of the solubilized matter,
the decanting sludges, the clarifying sludges or the filtration
cakes can be washed, and the washing waters are then combined with
the initial supernatant. All of the solutes can then be
concentrated.
[0097] The analysis of the harvested concentrated supernatants and
washing waters shows that 80% to 90% of the phosphorus contained in
the initial substrate is solubilized.
[0098] The use of exogenous phytase for the treatment of the wheat
bran does not improve the solubilization/recovery yield.
[0099] The solubilization of the wheat bran phosphorus without
recourse to exogenous phytase activity is particularly advantageous
since the provision of phytase not derived from GMOs (biological
regulation obligation) is difficult.
[0100] The solubilization of the phosphorus can then be added to by
more conventional treatments of bran or cake protein hydrolysis
(use of a mixture of endo and exopeptidases) and of wheat bran
starch saccharification (use of a mixture of amylase and
amyloglucosidase).
[0101] By way of example, the implementation of these various
treatments makes it possible to prepare clarified hydrolysates of
which the compositions are summarized in table III.
TABLE-US-00003 III Characteristics of the various wheat bran or soy
cake hydrolysates obtained after successive treatments in order to
hydrolyze the phytic acid then the proteins then the starch Soy
cake decoction Wheat bran decoction phytic acid hydrolysis by
phytic acid hydrolysis exogenous enzymes Characteristic of the +
protein + starch + protein clarified juice hydrolysis hydrolysis
hydrolysis Dry matter g/kg 51.3 81.2 81.4 83.5 116.6 Nitrogen % DM
4.9 3.8 4.0 4.2 8.3 P.sub.2O.sub.5 % DM 13.7 6.8 7.1 3.7 2.2 Sugar
monomer g/kg 15.6 23.8 43.2
[0102] It is particularly interesting to note that the
P.sub.2O.sub.5/DM contents of the clarified hydrolysates derived
from wheat bran are high.
Example 3
Production of Biological Yeast
[0103] The various hydrolysates resulting from the treatment of the
wheat bran or of the soy cake (example 2) were used for the
production of biological yeast, according to a conventional
industrial method for producing compressed yeasts.
[0104] As a whole, the tests proceeded very well at all levels of
the manufacturing cycle tested.
[0105] The growth yields observed during the parent yeast stages
are comparable to those normally noted with yeast autolysate.
[0106] No P.sub.2O.sub.5 deficiency was noted within
prefermentation or in first generation (G1 parent yeast) (table
IV).
[0107] The growth yields are very good.
[0108] The fermentative activity of this series of tests is overall
very satisfactory and equivalent to that of the reference tests.
The preservation of the friability of the compressed yeasts
produced is good.
[0109] In conclusion, the phosphorus resulting from the hydrolysis
of the phytic acid contained in the wheat bran, or the soy cake,
can therefore indeed be assimilated by the baker's yeast and allows
the manufacture of a quality yeast.
TABLE-US-00004 TABLE IV Phosphorus content noted during the
production of biological yeast (the phosphorus content is expressed
as % P.sub.2O.sub.5/yeast dry matter) Wheat bran Soy cake
hydrolysate hydrolysate Prefermentation 5.5 4.4 Parent yeast (G1)
1.8 1.8 Commercial yeast (G2) 1.7 to 2.1 1.5 to 1.6
* * * * *